No fatalities

7 Dec 2016: PIPER PA 34 200 — U S AVIATION GROUP LLC — Denton, TX

Denton, TX, United States

On 7 Dec 2016, a PIPER PA 34 200 operated by U S AVIATION GROUP LLC was involved in an aviation accident near Denton, TX. No fatalities were reported. Investigators recorded the probable cause as: The flight instructor’s decision to continue to taxi the airplane to the parking area with a known brake malfunction, which resulted in a loss of directional control and subsequent impact with a parked airplane. This summary draws on records from NTSB; 13 related events involving the same aircraft type or operator are linked below.

SourcesNTSBPrimary reportUpdated 1778583330Data APIEditorial standards

During an instructional flight, the flight instructor's brakes were inoperative while taxiing. During a turn in the parking area, the airplane struck a parked single-engine airplane, causing substantial damage to the left wing.

Incident Details

The accident occurred during an instructional flight in a multi-engine airplane. The flight instructor, seated in the right seat, reported that during the landing roll, the brakes on his side were inoperative, while the brakes operated by the pilot under instruction functioned normally. After landing, the instructor allowed the pilot under instruction to taxi to the parking area. During a right turn in the parking area, the pilot under instruction was instructed to apply both brakes. The airplane began to pull to the left. The instructor attempted to counteract the left pull by increasing the right engine speed, but this had no effect. Both engines were then shut down, but the airplane continued its leftward movement, and the left wing struck a parked single-engine airplane. The multi-engine airplane sustained substantial damage to the left wing.

Examination Findings

An examination of the brake assembly was conducted to identify any pre-accident mechanical malfunctions or failures that would have precluded normal operation. The examination determined that the right side brake actuator piston "o" ring had failed. This failure decreased hydraulic brake pressure, preventing proper brake function on the right side of the airplane.

Instructor's Remarks

The flight instructor stated that the accident could have been prevented if he had stopped on the taxiway and not entered the parking ramp.

Contributing factors

Causes

Instructor/check pilotBrake — Failure

Other contributing factors

Effect on operation